[Racefan]

I tried the excello pucks when thery first came out! What a mess! They left a residue all over the leaves of my plants and walls and everything else in the room. Nasty.
I'm the type that if your going to do it, do it right. These cheap set ups aren't always good things. Plus plants don't use co2 in the dark times and there isn't a way to control that with most of these homemade and cheap set ups.